Acoustical treatments designed to absorb and attenuate sound are well known and are embodied in wall treatments, ceiling treatments and floor treatments. In a stadium or arena, it is often desirable to provide acoustical treatments for sound diffusion and sound absorption. Indoor arenas are noted for their large ceiling structures including elongated structural beams and for their lack of acoustical treatments.
Crowd noise travels from its source in all directions including upwardly. In the typical indoor arena, crowd noise reflects off the ceiling and travels downwardly toward the playing surface. Placement of sound absorbing structures adjacent the ceiling would go a long way toward attenuating crowd noise in a manner that would be pleasing to the ear.
A need has, accordingly, developed for a sound absorbing device that can easily be mounted on or adjacent to the ceiling of an indoor arena to absorb crowd noise in an effective manner. It is with this need in mind that the present invention was developed.
The present invention relates to a suspended flexible sound absorbing banner. The present invention includes the following interrelated objects, aspects and features:
(1) In the preferred embodiment, the present invention includes a large rectangular flexible sound absorbing material, preferably made of fiberglass, and covered with a surface membrane such as NYLON material comprising a banner. The surface membrane may be porous, perforated or non-perforated and impermeable. It should have an appropriate mass layer and sufficient compliance to provide absorptive efficiency across a desired frequency range while having the structural strength to withstand a desired degree of tensioning.
(2) Opposed edges of the banner are clamped between pairs of elongated U-shaped cross-section spreader bars. Each opposed edge is clamped by bending the edge of the banner through four 90xc2x0 turns. A smaller dimensioned U-shaped spreader bar is receivable within a larger dimensioned U-shaped spreader bar and the two spreader bars may be clamped together with the edge of the banner clamped therebetween.
(3) At least two tension tabs consisting of elongated rigid bars are attached at spaced locations along the spreader bars. Such tension tabs include pre-formed holes designed to receive an attachment means for an elongated cable.
(4) The cables are stretched into attachment with adjacent structures of the ceiling of an arena such as, for example, parallel elongated I-beams. If desired, turnbuckles may be employed to tension the cables. Alternatively, tension adjustment may be accomplished through use of an adjusting bracket consisting of an elongated flexible piece of metal with a multiplicity of holes spaced along its length. A snap hook attached to a cable may be coupled to one of the spaced holes to create tension. The adjusting bracket is typically attached to an I-beam while the cable and snap hook are attached to the banner. When the cables are tensioned, the banner is stretched and the tension tabs pivot in response to this stretching action so that the banner is stretched to a generally planar configuration extending across a space parallel with the floor and ceiling of the arena. The strength of the sound transparent covering permits the tensioning of the system.
(5) The banner has been found to attenuate and absorb sound waves to an unexpected degree. Through the use of several suspended flexible sound absorbing banners in accordance with the teachings of the present invention, dramatic reduction in reflected noise may be achieved in an indoor arena.
As such, it is a first object of the present invention to provide a suspended flexible sound absorbing banner.
It is a further object of the present invention to provide such a device in which a generally rectangular large fiberglass-sailcloth combination is stretched across an arena parallel to the ceiling and floor thereof.
It is a still further object of the present invention to provide such a device in which two spreader bars are provided on each side of the banner and wherein edges of the banner are clamped therebetween.
It is a still further object of the present invention to provide coupling means adapted to couple elongated cables at spaced locations about the spreader bars to allow the banner to be stretched into desired configuration within an indoor arena.
These and other objects, aspects and features of the present invention will be better understood from the following detailed description of the preferred embodiment when read in conjunction with the appended drawing figures.